EPA 9078 SCREENING TEST METHOD FOR POLYCHLORINATED BIPHENYLS IN SOIL

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1、METHOD9078SCREENINGTESTMETHODFORPOLYCHLORINATEDBIPHENYLSINSOIL1.0SCOPEANDAPPLICATION1.1ThemethodmaybeusedtodeterminetheamountofPCB(polychlorinatedbiphenyl)contaminationinsoilssuchassand,gravel,loam,sediment,andclay,assumingthatPCBsarethesolesourceoforga

2、nichalogensinthesample.1.2Thiselectrochemicalmethodisdesignedtoprovidequantitativefieldresultsoverarangeof2to2000µg/gPCBs,significantlycuttingdownonthenumberofsamplesrequiringlaboratorytesting.1.3ChlorinesareremovedfromthePCBmoleculeusinganorgano-sodium

3、reagent.Theresultingchlorideionsaremeasuredusingachloridespecificelectrode.AnalystsmustidentifythetypeofAroclorcontaminationinordertousethisasaquantitativemethod.1.4Thismethodisrestrictedtousebyorunderthesupervisionoftrainedanalysts.Eachanalystmustdemon

4、stratetheabilitytogenerateacceptableresultswiththismethod.2.0SUMMARYOFMETHODAsampleofthesoiltobetestedisextractedwithahydrocarbonbasedsolvent.Theresultingextractisfilteredtoremovemoistureandinorganicsalts.Thedriedextractisreactedwithmetallicsodiumandaca

5、talysttostripchloridefromanyPCBthatmaybepresent.Theresultingchlorideionsareextractedintoanaqueousbuffersolutionwheretheyaredetectedusingachlorideionspecificelectrode.CAUTION:Someofthereagentsusedwiththistestingprocedurecontainflammablesolvents,diluteaci

6、ds,andmetallicsodium.Wearglovesandsafetyglasseswhileperformingtests.ReadallMSDSandwarningsincludedwiththeinstrumentbeforestartingtestingprocedure.3.0INTERFERENCES3.1Thisprocedureissensitivetoanychlorinatedcompoundthatispreferentiallysolubleinanon-polars

7、olvent.WhenanalyzingforPCBs,thepresenceofotherchlorinatedorganicswillresultinahighbias.Iodineandbrominecontainingcompoundswillaffectresultsifpresentinsignificantquantities.Wetordrysamplesmayberun,butresultsforallsamplesarecalculatedonawet-weightbasis.In

8、oneevaluationstudy(Table1),1.4%ofthemeasurementswerefalsenegatives.3.2Inorganicchloridesshouldnotinterfereusingthismethodifthesampleisextractedwithorganicsolvent.CD-ROM9078-1Revision0December19964.0APPARATUSANDMATERIALSElectroche